Advances in photolithography processes have enabled electromechanical systems, for example microelectromechanical systems (MEMS), to have extremely small features. It is not uncommon for these features to have dimensions in the order of micrometers. Because the integrated fabrication process does not involve direct manual modification and assembly, device fabrication may be extremely efficient and reliable. Furthermore, the photolithography process has enabled individual components to have extremely uniform geometry and performance, a major advantage in contrast to hand-assembled instruments. As a result, it has become possible to insert MEMS into a variety of applications.
As an example, pressure sensors are being integrated with automotive tires to provide real time monitoring of tire pressure, micro-machined drug delivery systems are being considered for use as implantable smart drug capsules, micro-inertia sensors are being used for smart projectiles to automatically adjust trajectory for gun jump and wind factors, and micro-machined digital propulsion is finding applications in controlling the position of micro-satellites.
Additionally, micromechanical structures and active components are integrated with electronic components (such as signal processing circuits), sensors (temperature, pH), optics, fluid components (such as fluid channels, micro-pumps, and micro-valves), and high-performance chemical analytical systems (such as electrophoresis) to realize comprehensive functional integration in “smart” sensors and actuators.
Some of these micro-mechanisms are dedicated to displacing an accurately integrated mobile part. Technology has advanced to a point where mobile micro-mechanisms with one or two dimension linear translation motion capability have been provided. However, providing for three dimension linear translation motion capabilities has proved more difficult.